Wolframin gene polymorphisms, including the H611R polymorphism, are reportedly associated with mood disorders and psychiatric hospitalization, but there is disagreement about the association of this specific variant with suicidality and impulsive traits. This study tested the association of the H611R polymorphism with mood disorders, suicidal behavior, and aggressive-impulsive traits. Two hundred and one subjects with mood disorders and 113 healthy volunteers were genotyped for the H611R polymorphism and underwent structured interviews for diagnosis and clinical ratings. All were Caucasians. The H611R polymorphism was associated with mood disorders but not suicidal behavior, aggressive/impulsive traits or suicidality in first-degree relatives. The HR heterozygote genotype was more frequent in mood disorder (chi(2)=7.505; df=2; p=.023). If this finding will be replicated, the H611R polymorphism may be a possible marker for mood disorders in a psychiatric population, and not just in relatives of Wolfram syndrome probands.